关键词: 数字高程模型, GIS, 水文信息提取, 巴中市

Abstract:

In order to discuss the technical issues of watershed hydrologic information extraction based on DEM and GIS, the hydrological analysis tool of Arc GIS was applied to study the extraction of hydrological information in Bazhong. The results showed that the relation between flow accumulation and drainage density or watershed area is a second derivative, which helps determine the confluence cumulative threshold value; the threshold influence the extraction of river basin in that the smaller the threshold is, the finer the extracted river network is; when threshold value reaches 8500, the extracted density and area of river network tends to be stable and matches well with the actual rivers; the actual terrain features, the possible original DEM data errors and other human factors affect the hydrology extraction results.

Key words: DEM, GIS；hydrological information extraction；Bazhong city